This application claims the benefits of Korean Patent Application No. 10-2005-0120078, filed on Dec. 8, 2005, and Korean Patent Application No. 10-2006-0088119, filed on Sep. 12, 2006, in the Korean Intellectual Property Office, the disclosures of which are incorporated herein in their entirety by reference.
1. Field of the Invention
The present invention relates to a fast handover method, and more particularly, to a fast handover method in which more than one candidate Internet protocol (IP) addresses are set.
2. Description of the Related Art
Conventional technology for preventing a packet loss during a handover of a mobile node is disclosed in U.S. Patent Publication No. 20040203740, entitled “Hybrid Wireless Bridge and Mobile Access Router System and Method.” The conventional technology is designed to provide a seamless service to a mobile node without an additional operation through a mobile Internet protocol (Mobile IPv4) by enabling the mobile node to perform a handover without an IP address when moving between sub-nets.
All network connection devices are connected to a central router, and the central router provides a connection point with an external network. Therefore, if a mobile node moves between sub-nets, news paths of packets toward the mobile node are controlled by the central router, and the mobile node, after performing a handover, can still receive a service without the help of the mobile Internet protocol. Since the mobile Internet protocol is not used, a delay caused by the use of the mobile Internet protocol can be reduced, and thus a seamless service can be provided to the mobile node.
Another conventional technology is disclosed in Korean Patent Publication No. 2005-0023194, entitled “Handover Method of Preventing Packet Loss in Mobile Internet Network.” This conventional technology relates to a handover method of a mobile connection terminal having mobility in a mobile Internet network. Specifically, in the conventional technology, connection information of a mobile connection terminal retained by a first base station connection device and a first packet connection router to which the mobile connection terminal is currently connected is transmitted to a second base station connection device and a second packet connection router. In addition, a tunnel is formed between the first packet connection router and the second packet connection router. Untransmitted packets in the first base station connection device are forwarded to the first packet connection router and then transmitted to the second base station device through the tunnel. The second base station connection device transmits the received packets to the mobile connection terminal.
RFC 4068 “Fast Handovers for Mobile IPv6 (FMIPv6)” standardized by an International Engineering Task Force (IETF) (www.ietf.org) MIPSHOP working group suggests a method of presetting a new care-of addresses (NCoA) and a method of forwarding a packet by binding a previous care-of address (PCoA) and an NCoA between a previous access router (PAR) and a mobile terminal in order to reduce a packet loss caused by the mobile terminal moving between IPv6 networks.